As technology for electronic communication develops recently, many electronic devices, e.g., a personal cellular phone or a tablet personal computer (PC), have been increasingly used and attention has been paid to electromagnetic waves resulting from the electronic devices.
Electromagnetic interference caused by noise resulting from high-density integration of electronic components and high speed in a signal processing speed is regarded as a factor determining an operation and reliability of various automation equipment and control devices.
A method has been widely used until recently for electromagnetic interference shielding, in which a shield layer is formed on a surface of, e.g., electronic components using a material having high electric conductivity and reflects electromagnetic waves to shield the electromagnetic waves.
However, the shielding merely based on the reflection of electromagnetic waves has only limited capability to shield electromagnetic waves generated in a wide range of frequencies. Accordingly, various technologies have been under development to solve such a problem.
Also, when electromagnetic waves generated in electronic components mounted in an electronic component package have an influence on electronic components mounted in an adjacent electronic component package, the shielding based on the reflection by conductive materials is also limited in removing such an influence.